Oil leak prevention structure for vacuum pump
AssigneeKabushiki Kaisha Toyota Jidoshokki
InventorsShinya Yamamoto, Masahiro Kawaguchi, Satoru Kuramoto
Life of this patent
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Abstract
A Roots pump rotates a plurality of rotors by a pair of rotary shafts to draw gas. Each rotary shaft extends through a rear housing member of the Roots pump. A plurality of stoppers are located on each rotary shaft to integrally rotate with the corresponding rotary shaft, and prevent oil from entering a fifth pump chamber of the Roots pump. Stoppers have a circumferential surface, respectively. Annular oil chambers collect oil. The oil chambers are located about an axis of the rotary shaft to surround the circumferential surface of the stopper. This effectively prevents oil from entering the pump chamber of the Roots pump.
Claims17
A vacuum pump that draws gas by operating a gas conveying body in a pump chamber through rotation of a rotary shaft, the vacuum pump comprising:
- an oil housing member, wherein the oil housing member defines an oil zone adjacent to the pump chamber, and the rotary shaft has a projecting section that projects from the pump chamber to the oil zone through the oil housing member;
- a stopper having a circumferential surface, wherein the stopper is located on the rotary shaft to integrally rotate with the rotary shaft and prevents oil from entering the pump chamber;
- and
- an annular oil chamber for collecting oil, wherein the oil chamber is located about an axis of the rotary shaft to surround the circumferential surface of the stopper.
A vacuum pump that draws gas by operating a gas conveying body in a pump chamber through rotation of a rotary shaft, the vacuum pump comprising:
- an oil housing member, wherein the oil housing member defines an oil zone adjacent to the pump chamber, and the rotary shaft has a projecting section that projects from the pump chamber to the oil zone through the oil housing member;
- a plurality of stoppers, each having a circumferential surface, wherein the circumferential surfaces have different diameters, wherein the stoppers are located on the rotary shaft to integrally rotate with the rotary shaft and prevent oil from entering the pump chamber;
- and
- a plurality of annular oil chambers for collecting oil, wherein each oil chamber is located about the axis of the rotary shaft to surround the circumferential surface of one of the stoppers, and wherein the oil chambers form a bent path extending from the side closer to the pump chamber to the side closer to the oil zone.
Dependencies are inferred from the claim text.